Details
| Original language | English |
|---|---|
| Pages (from-to) | 44-50 |
| Number of pages | 7 |
| Journal | PLANTA |
| Volume | 190 |
| Issue number | 1 |
| Publication status | Published - May 1993 |
Abstract
The plasma-membrane H+-pump in guard cells generates the driving force for the rapid ion fluxes required for stomatal opening. Since our electrophysio-logical studies revealed a two fold higher pump-current density in guard cells than in mesophyll cells of Vicia faba L. we elucidated the biochemical properties of this proton-translocating ATPase in plasma-membrane vesicles isolated from both cell types. The capability of the H+ -ATPase to create an H+ gradient is maintained in plasma-membrane vesicles derived from purified guard cells via blender maceration, high-pressure homogenization and polymer separation. The H+-pumping activity of these vesicles coincides with the presence of two polypeptides of approx. 100 and 92 kDa which are recognized by a monoclonal antibody raised against the plasma-membrane H+-ATPase from Zea mays L. coleoptiles. Comparison of H+-pumping activities of isolated membranes revealed an approximately two fold higher activity in guard cells than in mesophyll cells with respect to the total membrane protein content. Furthermore, we demonstrated by western blotting that the difference in pump activities resulted from a higher abundance of the electroenzyme per unit membrane protein in guard-cell plasma membranes. We suggest that the high H+-pump capacity is necessary to enable guard cells to respond to sudden changes in the environment by a change in stomatal aperture.
Keywords
- Guard cell, H-ATPase, Mesophyll cell, Patch-clamp, Plasma membrane, Proton pump (membrane density)
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Genetics
- Agricultural and Biological Sciences(all)
- Plant Science
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: PLANTA, Vol. 190, No. 1, 05.1993, p. 44-50.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Identification and biochemical characterization of the plasma-membrane H+-ATPase in guard cells of Vicia faba L.
AU - Becker, Dirk
AU - Zeilinger, Carsten
AU - Lohse, Gabi
AU - Depta, Hans
AU - Hedrich, Rainer
PY - 1993/5
Y1 - 1993/5
N2 - The plasma-membrane H+-pump in guard cells generates the driving force for the rapid ion fluxes required for stomatal opening. Since our electrophysio-logical studies revealed a two fold higher pump-current density in guard cells than in mesophyll cells of Vicia faba L. we elucidated the biochemical properties of this proton-translocating ATPase in plasma-membrane vesicles isolated from both cell types. The capability of the H+ -ATPase to create an H+ gradient is maintained in plasma-membrane vesicles derived from purified guard cells via blender maceration, high-pressure homogenization and polymer separation. The H+-pumping activity of these vesicles coincides with the presence of two polypeptides of approx. 100 and 92 kDa which are recognized by a monoclonal antibody raised against the plasma-membrane H+-ATPase from Zea mays L. coleoptiles. Comparison of H+-pumping activities of isolated membranes revealed an approximately two fold higher activity in guard cells than in mesophyll cells with respect to the total membrane protein content. Furthermore, we demonstrated by western blotting that the difference in pump activities resulted from a higher abundance of the electroenzyme per unit membrane protein in guard-cell plasma membranes. We suggest that the high H+-pump capacity is necessary to enable guard cells to respond to sudden changes in the environment by a change in stomatal aperture.
AB - The plasma-membrane H+-pump in guard cells generates the driving force for the rapid ion fluxes required for stomatal opening. Since our electrophysio-logical studies revealed a two fold higher pump-current density in guard cells than in mesophyll cells of Vicia faba L. we elucidated the biochemical properties of this proton-translocating ATPase in plasma-membrane vesicles isolated from both cell types. The capability of the H+ -ATPase to create an H+ gradient is maintained in plasma-membrane vesicles derived from purified guard cells via blender maceration, high-pressure homogenization and polymer separation. The H+-pumping activity of these vesicles coincides with the presence of two polypeptides of approx. 100 and 92 kDa which are recognized by a monoclonal antibody raised against the plasma-membrane H+-ATPase from Zea mays L. coleoptiles. Comparison of H+-pumping activities of isolated membranes revealed an approximately two fold higher activity in guard cells than in mesophyll cells with respect to the total membrane protein content. Furthermore, we demonstrated by western blotting that the difference in pump activities resulted from a higher abundance of the electroenzyme per unit membrane protein in guard-cell plasma membranes. We suggest that the high H+-pump capacity is necessary to enable guard cells to respond to sudden changes in the environment by a change in stomatal aperture.
KW - Guard cell
KW - H-ATPase
KW - Mesophyll cell
KW - Patch-clamp
KW - Plasma membrane
KW - Proton pump (membrane density)
UR - http://www.scopus.com/inward/record.url?scp=0002617899&partnerID=8YFLogxK
U2 - 10.1007/BF00195673
DO - 10.1007/BF00195673
M3 - Article
AN - SCOPUS:0002617899
VL - 190
SP - 44
EP - 50
JO - PLANTA
JF - PLANTA
SN - 0032-0935
IS - 1
ER -